Morning Glories Go 'Boing'?

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Morning Glories Go 'Boing'?

A little morning glory juice gave the first rubber its bounce, US researchers reported on Thursday. They said they had analyzed the chemical process involved and determined how a little sap from a flowering vine gave ancient Mayans and other people their national sport, as well as a material for making tools and medicine.

Writing in the journal Science, Dorothy Hosler and colleagues at the Massachusetts Institute of Technology said the morning glory juice started off critical chemical changes that changed sap from the rubber tree from sticky, brittle latex into stretchy elastic.

Spanish explorers described with astonishment the rubber that was produced by the Mayans and other peoples they met in Mexico and Central America. Most striking was a bouncy rubber ball used in a game that resembled modern-day basketball.

"Ancient Mesoamerican people harvested latex from Castilla elastica, processed it using liquid extracted from Ipomoea alba [a species of morning glory vine], and fashioned rubber balls, hollow rubber figurines, and other rubber artifacts from the resulting material," Hosler's team wrote.

"They used liquid rubber for medicines, painted with it, and spattered it on paper that was then burned in ritual. The ball game, played on a ball court with a solid rubber ball, was a key event in ancient Mesoamerican societies." To figure out how people learned to use rubber 3,000 years before vulcanization was invented, Hosler's team looked at rubber balls found in Veracruz, Mexico, some dating to 1600 BC.

They also traveled to Chiapas in Mexico to see how traditional workers made rubber. First the workers collected latex from the Castilla trees; then they collected the morning glory vines, crushed them, and squeezed the juice into a bucket containing the latex.

"After approximately 15 minutes of stirring, the liquid latex solidified into a white mass, which was then removed from the bucket and formed by hand into a solid ball 3.7 inches in diameter," they wrote.

"When bounced on the ground, the ball exhibited typical rubbery behavior, rebounding into the air to a height of about 6 feet."

The researchers made nuclear magnetic resonance scans of the ancient balls and the modern ones, analyzing their chemical structure. They found that adding the morning glory juice purified the latex and changed its chemical properties, giving it the bounciness and elasticity that identify rubber.